As a prior art technique of the coated cutting tool, there may be mentioned a cutting tool made of a surface-coated tungsten carbide-based cemented carbide which comprises a hard coating layer constituted by a titanium nitride layer and a titanium carbonitride layer each having a granular crystal structure being alternately laminated two or more layers having an average layer thickness of 3 to 10 μm on a surface of the tungsten carbide-based cemented carbide substrate, and at least one layer of the titanium carbonitride layers has a lengthwise grown crystal structure (for example, see Patent Literature 1.).
Also, a cutting tool made of a surface-coated cemented carbide which comprises a WC-based cemented carbide substrate on the surface of which being formed a multi-layered coating layer comprising an alternately laminated layers of TiN and TiCN using a chemical vapor deposition method with a layer thickness of 1 to 5 μm may be mentioned as the prior art technique of the coated cutting tool (for example, see Patent Literature 2.).